Post Offices List in New Castle City, Pennsylvania:
| Downtown New Castle Post Office | 151 Cascade Galleria, New Castle, PA 16101 |
| Neshannock Post Office | 4 E Maitland Ln, New Castle, PA 16105 |
| New Castle Post Office | 435 S Cascade St, New Castle, PA 16108 |
| New Castle Post Office | 435 S Cascade St, New Castle, PA 16108 |